Substrate processing method and substrate processing apparatus

ABSTRACT

The wafer coated with the resist is deliberately placed in the vapor before being transferred to an aligner that exposes the resist on the wafer, the vapor, for example, the moisture, uniformly adheres onto the resist on the wafer. As a result, the substrate can uniformly be exposed in the following exposing process, and the uniformity of the line width and the like can be improved.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a substrate processing apparatus forcoating a semiconductor wafer with a resist and developing thereof in afabrication of semiconductor device. In detail, the invention relates toa substrate processing apparatus that controls the atmosphere of theprocessing environment of the substrate.

2. Description of the Related Art

In a process of photolithography in the semiconductor devicefabrication, the surface of a semiconductor wafer (hereinafter referredto as “a wafer”) is coated with a photo-resist, exposing a mask patternon the resist, then developing thereof, forming a resist pattern on thewafer surface. The resist coating and development are performed in anintegrated coating and developing processing apparatus including athermal processing apparatus such as a heating processing apparatus or acooling processing apparatus. The coating and developing apparatus isconnected to the aligner through an interface portion and thesemiconductor device fabrication is actually performed.

In the coating and developing apparatus, when processing of wafer isperformed, in order to prevent impurity such as particles from adheringto the wafer, the air cleaned with an air cleaner is supplied to theinside of the coating and developing processing apparatus as a down flowof air current, so that the wafer is processed in the clean condition.

However, these days, laser-beam light source with a short wavelengthlike, for example, F₂ excimer laser (157 nm) is used in an aligner tocope with the miniaturization of the devices, therefore in case thatimpurities of molecule level, which had not been a problem up to now,such as oxygen, ozone, water and organic matter, adheres on the resistfilm coated on the wafer in the steps performed before the exposure,absorption and scattering of light caused by the impurities tend tooccur. When moisture adheres on the resist film, 2% of the light will beabsorbed with film thickness of every 10 Å (1 mm), and when the watermolecules exist scattering on the wafer surface, difference arises inamount of exposure between the portion with water molecules and theportion without the water molecules which causes deterioration in theuniformity of line width of the pattern. The down flow of the airdescribed above is not able to remove the impurities of molecule level.

SUMMARY OF THE INVENTION

Considering the above-described circumstances, an object of the presentinvention is to provide a substrate processing method and substrateprocessing apparatus that improves the uniformity of line width evenunder a circumstance in which the impurities of molecule level exists.

To accomplish the above-described objects, the substrate processingmethod of the present invention comprises the steps of (a) coating aresist on the substrate and (b) placing the substrate coated with theresist in an atmosphere including a vapor. According to the aforesaidstructure, for example, the vapor, such as water vapor uniformly adheresto the resist on the substrate by deliberately placing the substrateinto the vapor before transferring thereof to an aligner that exposesthe resist coated on the substrate. Therefore, the substrate coulduniformly be exposed in the following exposing step, and the uniformityof the line width can be improved. Here, in order to have the moistureadhere uniformly on the substrate, a saturated vapor is preferably usedin this case.

Another embodiment of the present invention further comprises the stepsof (c) drying the substrate after the step (b) so that moisture adheredto the substrate remains on the surface of the substrate. In suchmanner, the moisture once adhered uniformly on the substrate isdecreased by performing drying process uniformly so that the moistureadhered onto the surface of the substrate remains thereon. With thismethod, exposing process can be performed appropriately, thus the amountof exposure reaching the resist can be increased as much as possiblewhile keeping the amount of exposure in the exposing step constant. Inthis case, in order to perform drying process uniformly on thesubstrate, heating the substrate is preferable as a drying process andthe moisture adhered on the substrate to be evaporated uniformly.Alternatively, drying may be performed with supplying heating airuniformly all over the substrate.

According to another embodiment of the present invention, the step (b)has a step of controlling a pressure of the atmosphere around thesubstrate. The amount of evaporating moisture adhered on the substrateplaced in the vapor can be controlled by controlling the pressure.Especially, another embodiment of the present invention is that the step(d) has the step of controlling the pressure so that the pressurebecomes higher than an atmospheric pressure for a predetermined timeperiod beginning from when the substrate is started to be placed in thevapor and the step of controlling the pressure so that the pressurebecomes lower than the atmospheric pressure after the predetermined timeperiod. As a result, the amount of moisture evaporate from the substratecan be restrained beginning from when the substrate is started to beplaced in the vapor until the predetermined time passes, which causesacceleration in the effect of adhering moisture uniformly on thesubstrate. In addition, after the predetermined time, the moistureadhered onto the surface of the substrate is evaporated actively, forexample, the substrate is subjected to the uniform drying process sothat the moisture on the surface of the substrate is decreased to apredetermined amount. With this embodiment, the amount of exposurereaching the resist can be increased as much as possible while keepingthe amount of exposure in the exposing step constant.

A substrate processing apparatus of the present invention comprises, acoating processing portion coating a resist on the substrate, a vaporprocessing portion placing the substrate coated with the resist in anatmosphere including a vapor and a transfer mechanism transferring thesubstrate at least between the coating processing portion and the vaporprocessing portion.

According to the aforesaid structure, the substrate is, for example,transferred to the vapor processing portion with the transfer mechanismbefore delivering thereof to the aligner that exposes the resist coatedon the substrate. The vapor such as water vapor uniformly adheres to theresist on the substrate by deliberately placing the substrate therein.Therefore, the substrate could uniformly be exposed in the followingexposing process, and the uniformity of the line width and the like canbe improved. In order to have moisture uniformly adhere on thesubstrate, the vapor used in this case is preferred to be a saturatedvapor.

Another embodiment of the present invention further comprises a dryingprocessing portion drying the substrate so that the moisture adheres toa surface of the substrate remains thereon. The amount of moistureadhered uniformly on the substrate is decreased so that the moistureadhered on the surface of the substrate remains thereon in the dryingprocessing portion of this kind. With this method, exposing process canbe performed appropriately, thus the amount of exposure reaching theresist can be increased as much as possible while keeping the amount ofexposure in the exposing step constant. In this case, in order toperform drying process uniformly on the substrate, drying by heating thesubstrate with a heating plate to have the moisture adhered to thesubstrate evaporate uniformly is preferable. Alternatively, drying canbe performed with supplying heated air uniformly all over the substrate.Furthermore, the drying processing portion may be provided inside thevapor processing portion. Alternatively, the drying processing portioncan be provided outside the vapor processing portion, and the substratemay be transferred between the vapor processing portion and the dryingprocessing portion with, for example, the transfer mechanism.

According to another embodiment of the present invention, the vaporprocessing portion has a pressure controlling portion controlling apressure of the atmosphere around the substrate. Especially the pressurecontrolling portion is preferred to control the pressure so that thepressure becomes higher than an atmospheric pressure for a predeterminedtime period beginning from when the substrate is started to be placed inthe vapor and control the pressure so that the pressure becomes lowerthan the atmospheric pressure after the predetermined time period.

These and other objects, features and advantages of the presentinvention will become more apparent in light of the following detaileddescription of a best mode embodiment thereof, as illustrated in theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a coating and developing processing apparatusaccording to a first embodiment of the present invention.

FIG. 2 is a front view of the coating and developing processingapparatus shown in FIG. 1.

FIG. 3 is a rear view of the coating and developing processing apparatusshown in FIG. 1.

FIG. 4 is a sectional view of a vapor processing unit relating to thefirst embodiment of the present invention.

FIG. 5 is a flow chart showing a series of processing steps of thecoating and developing processing apparatus.

FIG. 6 is a sectional view of the vapor processing unit relating to thesecond embodiment of the present invention.

FIG. 7 is a sectional view of the vapor processing unit relating to thethird embodiment of the present invention.

FIG. 8 is a sectional view, showing the case when the heating process isperformed in the vapor processing unit shown in FIG. 7.

FIG. 9 is a sectional view of a vapor processing unit according to thefourth embodiment of the present invention.

FIG. 10 is a perspective view of the unit supplying ultra-pure water orvapor from the nozzle by roating the substrate.

FIG. 11 is a sectional view of a vapor processing unit according to thefifth embodiment of the present invention.

FIG. 12 is a sectional view of a vapor processing unit according to thesixth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Preferred embodiments of the present invention will be explained belowwith reference to the drawings.

FIG. 1, FIG. 2 and FIG. 3 are diagrams showing a total configuration ofa coating and developing processing apparatus according to an embodimentof the present invention. FIG. 1 is a plan view, FIG. 2 is a front view,and FIG. 3 is a rear view.

The coating and developing processing apparatus 1 has a structure inwhich a cassette station 10 provided for carrying a plurality of, forexample, twenty-five semiconductor wafers W as substrates to beprocessed in a wafer cassette CR, as a unit, to the inside the apparatus1 and carrying thereof to the outside of the apparatus 1 and alsocarrying in the substrates from the wafer cassette CR and carrying outthe substrates from the cassette CR; a processing station 11 in whichvarious kinds of processing units each for performing predeterminedprocess for the semiconductor wafers W one by one in coating anddeveloping processing steps that are multi-tiered; and an interfaceportion 12 for delivering and receiving the semiconductor wafer W withan aligner 13 disposed adjacent to the processing station 11, areintegrally connected.

In the cassette station 10, as shown in FIG. 1, a plurality of, forexample, up to four cassettes CR are placed in a line of an X-directionat positions of projections 20 a provided for alignment thereof on acassette mounting table 20, with respective outlet and inlet ports forthe wafer W facing the processing station 11. A wafer transfer mechanism21 movable in the direction of arrangement of the cassettes (anX-direction) and in the direction of arrangement of the wafers housed inthe wafer cassette CR (a Z-direction) is structured to be selectivelyaccessible to each of the wafer cassettes CR. Further, the wafertransfer mechanism 21 is structured so that it can be rotated inθ-direction so as to be accessible to a transfer and alignment unit(ALIM) and an extension unit (EXT) included in a multi-tiered unitportion of a third unit group G3 disposed at the processing station 11side, as will be described later.

In the processing station 11, as shown in FIG. 1, a vertical carriertype of a main wafer transfer mechanism 22 is provided at a center,around which a group of or a plurality of groups of all processing unitsare multi-tiered. In this example, five processing unit groups G1, G2,G3, G4 and G5 are disposed multi-tiered. The multi-tiered units of thefirst and the second unit groups G1 and G2 are disposed on the frontside of the apparatus adjacent with each other (the front in FIG. 1).The multi-tiered unit of the third unit group G3 is disposed adjacent tothe cassette station 10 and the multi-tiered unit of the fourth unitgroup G4 is disposed adjacent to the interface portion 12. Themulti-tiered unit of the fifth unit group G5 is disposed on the backside In addition, the fifth unit group G5 is structured to be movablealong the rail 25 for maintenance of the main wafer transfer mechanism22.

As shown in FIG. 3, the main wafer transfer mechanism 22 has a wafertransfer device 46 that is capable of moving up and down in verticaldirection (the Z-direction) inside a cylindrical supporter 49. Thecylindrical supporter 49 is connected to a rotating shaft of a motor(not shown) and rotates integrally with the wafer transfer device 46around the aforesaid rotating shaft by a rotational driving force of themotor. Thereby the wafer transfer device 46 can be rotated inθ-direction. The wafer transfer device 46 has, for example, three pairsof tweezers 48 moving forwards and backwards on a pedestal 47. Thetweezers 48 holds and transfers the wafer.

As shown in FIG. 2, in the first unit group G1, two spinner-typeprocessing units for performing predetermined processing while the waferW is placed on a spin chuck in a cup CP, for example, a resist coatingunit (COT) and a developing processing unit (DEV) are two-tiered fromthe bottom in order. Also in the second unit group G2, two spinner-typeprocessing units, for example, the resist coating unit (COT) and thedeveloping processing unit (DEV) are two-tiered from the bottom inorder. Since the drainage of a resist solution is troublesome in termsof both mechanism and maintenance in the resist coating processing unit(COT), it is preferable to place the resist coating unit at the lowertier. However, it is possible to place thereof on the upper tier asnecessary.

As shown in FIG. 3, in the third unit group G3, oven-type processingunits each for performing predetermined processing while the wafer W isplaced on a mounting table, for example, a cooling unit (COL), anadhesion unit (AD) an alignment unit (ALIM), an extension unit (EXT), apre-baking unit (PAB), a post-baking unit (POB) are stacked from thebottom in order. Also in the fourth unit group G4, oven-type processingunits, for example, two cooling units (COL), an extension and coolingunit (EXTCOL), an extension unit (EXT), a pre-baking unit (PAB) and apost-baking unit (POB) are stacked from the bottom in order.

By disposing the cooling unit (COL) and the extension unit (EXT),processing units with low processing temperature on the lower tier anddisposing the baking unit (PAB) and the post-baking unit (POB),processing units with high processing temperature on the upper tier,thermal interference between the units can be reduced. However, it isalso possible to dispose multi-tiered at random.

The interface portion 12 has the same size as the processing station 11in the depth direction, but smaller in the width direction. A portablepickup cassette CR and a fixed-type buffer cassette BR are disposed intwo tiers at the front of the interface portion 12. A vapor processingunit 30, according to the present invention is disposed at the back. Inthe center, a wafer transfer mechanism 24 is disposed. The wafertransfer mechanism 24 moves in the X- and the Z-direction to get accessto both cassettes CR and BR, and the vapor processing unit 30. The vaporprocessing unit 30 will be described later. The wafer transfer mechanism24 is structured so that it can be rotated in θ-direction so as to beaccessible to the extension unit (EXT) disposed in a multi-tiered unitportion of the fourth unit group G4 disposed at the processing station11 side and to a transferring table (not illustrated) adjacent to thealigner 13 side.

As shown in FIG. 1, the interface portion 12 is surrounded by a wallmember 15, and isolated from the outside atmosphere of the coating anddeveloping processing apparatus 1. With this configuration, for example,inside of the interface portion 12 surrounded by the wall member 15 ispurged with nitrogen gas or heating air to regulate oxygen concentrationand humidity (moisture content) to low level. For example, the oxygenconcentration is adjusted to be 1 ppm and moisture content to be 1 ppm.Further, openings 15 a and 15 b transferring the wafer W to theprocessing station 11 and to the aligner 13 respectively, are formed onthe wall member 15 and the openings are structured to be able to openand close by a shutter (not shown) In such manner, by controlling theatmosphere inside the interface portion 12 precisely, impurities such asoxygen and moisture adhering to the wafer right before the exposingprocess with the aligner 13 can be prevented.

FIG. 4 is a sectional view of the vapor processing unit 30 relating tothe above-mentioned first embodiment. In this vapor processing unit 30,for example, on an upper portion of cylindrically shaped holding table34, provided for holding the wafer W, for example, a cylindricallyshaped lid 32 is disposed. A lifting mechanism 26 configured of an aircylinder enables the lid 32 to be lifted and lowered. An O-ring for sealis attached to the lower end of the lid 32. When the lid 32 is loweredby the lifting mechanism 26, a processing chamber R is formed as thelower end portion thereof touches the holding table 34.

A plurality of holes 34 a, for example three, pierces through theholding table 34. Three Support pins 29 supporting the wafer W from theback side are provided and a lifting cylinder 36 enables the supportpins 29 to protrude and sink to the surface of the holding table 34through the holes 34 a. Thereby, the wafer W can be delivered to andreceived from the wafer transfer mechanism 24.

In addition, around the edge portion of the holding table 34, aplurality of supply ports 34 b supplying vapor into the processingchamber R are provided. The vapor, for example, is supplied from a vaporgenerator 35 through a supply pipe 38 with a pump 28. The vaporgenerator 35 vaporizes, for example, ultra-pure water 39 by heatingthereof with a heater 37. At the supply pipe 38, a regulating valve 27regulating pressure and flow rate of the vapor is provided.

Inside the lid 32, a sensor 33 measuring humidity inside the processingchamber R is provided. The amount of vapor supplied can be controlledcorresponding to, for example, the measuring result of the sensor 33.

A series of processing steps in the coating and developing processingapparatus 1 explained above will be explained with reference to the flowchart shown in FIG. 5.

First, in the cassette station 10, the wafer transfer mechanism 21 getsaccess to the cassette CR on the cassette mounting table 20, housingunprocessed wafers and takes one wafer W out of the cassette CR andtransfers to the alignment unit (ALIM). After the alignment unit (ALIM)aligns the wafer W (step 1), the wafer W is transferred to the adhesionunit (AD) with the main wafer transfer mechanism 22 where hydrophobicprocess is performed (step 2) then to the cooling unit (COL) where apredetermined cooling process is performed (step 3). Thereafter, thewafer is transferred to the resist coating processing unit (COT) and theresist is spin coated thereon (step 4). Then a predetermined heatingprocess is performed in the pre-baking unit (PAB) (step 5) followed bycooling process in the cooling unit (COL) (step 6). After that, in theinterface portion 12, the wafer is transferred to the vapor processingunit 30 with the wafer transfer mechanism 24.

In the vapor processing unit 30, the wafer W is delivered to thesupporting pins 29 on the holding table 34, and as the supporting pins29 lowers, the wafer W is placed on the holding table 34 while the lid32 is in its upper position. Then the lid 32 is lowered and theprocessing chamber R is formed (FIG. 4). Next, the vapor is suppliedinto the processing chamber R from the vapor generator 35 and the vaporis uniformly adhered to the front surface of the resist film. With thisconfiguration, the wafer can uniformly be exposed in the followingexposing process and the uniformity of the line width can be improved(step 7).

In other words, according to the present embodiment, the amount ofexposure reaching to the resist decreases as the vapor uniformly adhereson the resist, however, the wafer can uniformly be exposed compared withthe prior art where the moisture exists scattered on the wafer. Thedecrease in the amount of exposure can be prevented with raising theintensity of the exposure. Also, regarding the supply of the vapor, itis preferable to have the processing chamber R saturated with vapor. Inother words, the saturation causes the humidity to be approximately100%, amount of moisture is increased as much as possible, therebyenabling the vapor to adhere more uniformly on the wafer. The second andthe following embodiments described below also carry out vaporprocessing with the saturated vapor. However, it is not always necessaryto process in the saturated state.

The wafer transfer mechanism 24 transfers the wafer W to the aligner 13and the exposing process is performed therein (step 7). After theexposing process, the heating process in the post exposure baking unit(PEB) is performed (step 8). After that, the wafer W is transferred tothe developing processing unit (DEV) and the developing process isperformed (step 9). Then the predetermined heating process is performedin the post-baking unit (POB) (step 10). Thereafter the wafer W issubjected to a predetermined cooling process in the cooling unit (COL)(step 11), and returned to the cassette CR through the extension unit(EXT).

FIG. 6 is a sectional view showing a vapor processing unit according tothe second embodiment of the present invention. Incidentally in FIG. 6,the same numerals and symbols will be used to designate the samecomponents as those in FIG. 4, and the explanation thereof will beomitted. A heating plate 43 heating the wafer W by placing the wafer Wthereon is disposed on the holding table 41 in the vapor processing unit40. The heating plate 43 has, for example, a heater 45 and the wafer Wis heated thereby. On the heating plate 43, three holes 43 a are formedand the supporting pins 29 protrude and sink therethrough. With suchconfiguration, the wafer W can be delivered and received from theoutside. Meanwhile, a supply port 41 a for supplying the vapor from thevapor generator 35 into the processing chamber R is formed on theholding table 41.

With regard to the processing steps of the vapor processing unit 40,first of all, the wafer W is placed on the heating plate 43 and the lid32 is lowered to form the processing chamber R. Then, the vapor issupplied into the processing chamber R from the vapor generator 35 andadhered uniformly onto the front surface of the resist film. With thisstructure, the wafer can uniformly be exposed in the following exposingprocess and the uniformity of the line width and the like can beimproved.

Next, the wafer W is heated with the heating plate 43 at a predeterminedtemperature for a predetermined time period. With this method, themoisture adhered on the wafer W can be evaporated so that the moistureremains on the surface of the wafer W. In such manner, the moistureadhered uniformly on the substrate is decreased by heating the wafer Wuniformly so that the moisture adhered to the surface thereof remainsthereon, in other words, the drying process is being performed to thewafer W. This enables the exposing process to be performedappropriately, thus the amount of exposure reaching the resist can beincreased as much as possible while keeping the amount of exposure inthe exposing step constant.

FIG. 7 is a sectional view showing a vapor processing unit according tothe third embodiment of the present invention. Incidentally in FIG. 7,the same numerals and symbols will be used to designate the samecomponents as those in FIG. 4, and the explanation thereof will beomitted. A similar apparatus to the vapor processing unit in FIG. 4 isdisposed inside the case 44 in the vapor processing unit 50. Atransferring body 52 moving horizontally along with a rail 42 with thecylinder mechanism or a belt mechanism is disposed adjacent to theapparatus. A heating plate 43 supported by the supporting plate 51 isprovided on the transferring body 52. In addition, according to theembodiment, a supply port 32 a is formed at the side portion of the lid32, as illustrated, and the vapor from the vapor generator 35 issupplied into the processing chamber R through the supply port 32 a Inthe case 44 an opening 44 a is provided for delivering the wafer W toand receiving the wafer W from the outside.

With regard to the processing steps of the vapor processing unit 50,first of all, when the wafer W is placed on the holding table 34 withthe holding pins 29, the lid 32 lowers to form the processing chamber R.Then, the vapor is supplied into the processing chamber R from the vaporgenerator 35 and uniformly adheres on the surface of the resist film onthe wafer. In such manner, the wafer can uniformly be exposed in thefollowing exposing process and the uniformity of the line width and thelike can be improved.

Next, as shown in FIG. 8, the lid 32 rises and the transferring body 52approaches. Then the heating plate 43 moves to right above the wafer Wand stops subjecting the wafer W to the heating process at apredetermined temperature for a predetermined time period. In suchmanner, similar to the second embodiment described above, the moistureadhered on the wafer W can be evaporated so that the moisture remains onthe surface thereof. This causes the exposing process to be performedappropriately, thus the amount of exposure reaching the resist can beincreased as much as possible while keeping the amount of the exposurein the exposing step constant.

FIG. 9 is a sectional view showing a vapor processing unit according tothe fourth embodiment of the present invention. Incidentally, in FIG. 9,the same numerals and symbols will be used to designate the samecomponents as those in FIG. 4, and the explanation thereof will beomitted. In the central portion of the lid 32 in the vapor processingunit 60, an air supply port 32 b is formed for supplying air into theprocessing chamber R from the air supply source 54 through a supply pipe57. The air from the air supply source 54 is supplied heated, forexample, with a heater 55 to a predetermined temperature, for example,50° C. to 100° C. On the inside ceiling of the lid 32, a defusing member56 is attached for defusing the air supplied as above uniformly insidethe processing chamber R. A plurality of small holes 56 a are formed onthe defusing member 56. In such manner, the air spreads out as far asthe edge of the wafer W.

Furthermore, although not illustrated, similar to each of the aforesaidembodiments, the vapor is supplied from the supply port 34 b of theholding table 34 in this embodiment.

According to the present embodiment, first of all, the vapor is suppliedand the vapor uniformly adheres to the front surface of the resist filmcoated on the wafer W. Next, the drying process is performed blowingheating air onto the surface of the wafer W, causing the moistureadhered on the wafer W to evaporate so that the moisture remains on thesurface of the wafer W.

With such processing method, similar to each of the aforesaidembodiments, the amount of exposure reaching the resist can be increasedas much as possible while keeping the amount of exposure in the exposingstep constant.

The present invention is not limited to an embodiment as describedabove, however, various kinds of modification is possible.

For example, as shown in FIG. 10, the wafer W can be spun in θ-directionwhile being held with a spin chuck 63 which rotatably holds the wafer Wand ultra-pure water is supplied onto the surface of wafer W with astick-shaped supply nozzle 69 having a slit shaped discharge opening(not shown) and the moisture may be adhered uniformly on the wafer Wcoated with the resist. In addition, in this case, the vapor may begushed out from the supply nozzle 6 c while rotating the wafer W.

The holding table 34 as shown in FIGS. 7 and 8, may be replaced with,for example, a cooling plate having a cooling means such as coolingwater or Peltier element. With this embodiment, a cooling process by thecooling plate can be performed after the heating process performed withthe transferring body 52 as shown in FIG. 8. Throughput can be improvedcompared to a case, for example, where the wafer is transferred toanother cooling unit for the cooling process to be performed.

Furthermore, a semi-conductor wafer is used as a substrate in each ofthe embodiments described above, however, the present invention can alsobe applied to a substrate such as a glass substrate used for a liquidcrystal display and the like.

FIG. 11 is a sectional view showing a vapor processing unit according tothe fifth embodiment of the present invention. Incidentally in FIG. 11,the same numerals and symbols will be used to designate the samecomponents as those in FIG. 4, and the explanation thereof will beomitted.

A vapor processing unit 70 has an increasing and reducing pressureapparatus 72. A pipe 75 is connected between the increasing and reducingpressure apparatus 72 and an air introduction and exit port 73 providedon the lid 32 and the increasing and reducing pressure apparatus 72controls the pressure inside the processing chamber R under control of acontroller 71. As the increasing and reducing pressure apparatus 72, avacuum pump and the like which introduces air into and sucks out the airout of the processing chamber R can be used.

A pressure measuring sensor 74 is attached, for example, to the insideof the lid 32. The pressure measuring sensor 74 detects the pressureinside the processing chamber R and the controller 71 controls theincreasing and reducing pressure apparatus 72 corresponding to thedetected results of the pressure measuring sensor 74.

In the vapor processing unit 70 structured as above, the pressure insidethe processing chamber R is controlled, therefore, the amount of wateradhered to the wafer W as a result of the vapor processing can beadjusted. Thus, dryness of the wafer can freely be controlled.

One example of an operation of the vapor processing unit 70 structuredin such manner will be described fully. First, after the wafer W isplaced on the holding table 34 and the lid 32 is lowered and becomehermetically sealed, the vapor is supplied into the processing chamber Rwith the vapor generator 35. Then, the increasing and reducing pressureapparatus 72 is activated, for example, while the vapor flowing into theprocessing chamber R or after the inflow of the vapor is stopped, sothat the pressure inside the processing chamber R becomes bigger, forexample, than the atmospheric pressure. In such manner, the vaporevaporated from the substrate can be restrained for a predetermined timeperiod starting from the exposure of the substrate to the vapor, and theeffect of adhering the vapor uniformly on the substrate is encouraged.The predetermined time period may be, for example, several seconds toseveral minutes, the same can be applied to the examples hereafter.

On the other hand, after the predetermined time period is passed, thepressure inside the processing chamber R is adjusted to be smaller thanthe atmospheric pressure. As a result, after the predetermined timeperiod is passed, the moisture adhered on the surface of the wafer W isactively vaporized and the drying process can be performed uniformly,for example, up to a point where the predetermined amount of moistureremains on the surface of the wafer W. In other words, drying processunder reduced pressure may be performed. With this method, the amount ofexposure reaching the resist can be increased as much as possible, whilekeeping the uniformity in the amount of exposure in the exposing stepconstant.

FIG. 12 is a sectional view showing a vapor processing unit according tothe sixth embodiment of the present invention. Incidentally, in FIG. 12,the same numerals and symbols will be used to designate the samecomponents as those in FIG. 4, and the explanation thereof will beomitted.

In a vapor processing unit 80, a moisture film thickness measuringapparatus 81 is attached inside the lid 32. The moisture film thicknessmeasuring apparatus 81 measures the film thickness of the vapor adheredto the surface of the wafer W, after the wafer W is exposed to thevapor. As the moisture film thickness measuring apparatus 81, forexample, an apparatus using a principle of measuring the film thicknesswith light interference can be used.

A controller 82 controls switching of the pump 28 corresponding to themeasurement result of the moisture film thickness measuring apparatus81, therefore, the amount of vapor supplied into the processing chamberR can be controlled.

One example of an operation of the vapor processing unit 80 structuredin such manner will be described concretely. First, after the wafer W isplaced on the holding table 34, the lid 32 is lowered to becomehermetically sealed, the vapor is supplied into the processing chamber Rwith the vapor generator 35. Then, for example, while the vapor isflowing into the processing chamber R, the moisture film thicknessmeasuring apparatus 81 measures the film thickness of the moistureadhered on the surface of the wafer W. A controller 82 controlsswitching of the pump 28 corresponding to the measurement result,therefore, the amount of vapor supplied into the processing chamber R iscontrolled. One example of an operation of the vapor processing unit 70structured in such manner will be described concretely. First, after thewafer W is placed on the holding table 34, the lid 32 is lowered tobecome hermetically sealed, the vapor is supplied into the processingchamber R with the vapor generator 35. Then, for example, while thevapor is flowing into the processing chamber R, the moisture filmthickness measuring apparatus 81 measures the film thickness of themoisture adhered on the surface of the wafer W. After that, for examplewhen the moisture film thickness reaches to a predetermined value, thesupply of the vapor is stopped. With this configuration, an appropriateamount of vapor can uniformly be adhered onto the surface of the waferW. As a result, a minimum amount of moisture can be adhered onto thewafer W by supplying minimum amount of vapor, therefore, excessivesupply of vapor can be prevented. In the same time, the drying processdescribed in the above mentioned second and third embodiments and thelike can be omitted, which causes the processing time to be shortened.

Incidentally, according to the sixth embodiment, the measurement of themoisture film thickness measuring apparatus 81 may not be included inthe above-mentioned processing unit 80, but may be included in aseparate measuring unit. In that case, the vapor processed wafer may betransferred to the separate measuring unit after the completion of thevapor process in the vapor processing unit, and the measurement with themoisture film thickness measuring apparatus 81 may be performed.

Moreover, instead of using the moisture film thickness measuringapparatus 81, for example, wetting condition on the surface of the waferW may be picked up as an image using an image pick-up apparatus like aCCD camera.

As described above, according to the present invention, by placing asubstrate coated with resist in vapor, moisture adheres uniformly on theresist of the substrate, therefore, the uniform exposure can be realizedin an exposing step, and uniformity of the line width and the like canbe improved.

The disclosure of Japanese Patent Application No.2001-358183 filed Nov.22, 2001 including specification, drawings and claims are hereinincorporated by reference in its entirety.

Although the present invention has been shown and described with respectto a best mode embodiment thereof, it should be understood by thoseskilled in the art that the foregoing and various other changes,omissions, and additions in the form and detail thereof may be madetherein without departing from the spirit and scope of the presentinvention.

1-9. (canceled)
 10. An apparatus for processing a substrate, comprising:a coating processing portion coating a resist on the substrate; a vaporprocessing portion placing the substrate coated with the resist in anatmosphere including a vapor; and a transfer mechanism transferring thesubstrate at least between the coating processing portion and the vaporprocessing portion.
 11. The apparatus as set forth in claim 10, whereinthe vapor processing portion places the substrate coated with the resistin a saturated vapor atmosphere.
 12. The apparatus as set forth in claim10, further comprising: a drying processing portion drying the substrateso that a moisture adheres to a surface of the substrate remainsthereon.
 13. The apparatus as set forth in claim 12, wherein the dryingprocessing portion has a heating plate heating the substrate.
 14. Theapparatus as set forth in claim 12, wherein the drying processingportion has means for supplying the substrate with a heating air. 15.The apparatus as set forth in claim 10, wherein the apparatus isdisposed adjacent to an aligner, the apparatus further comprising: adelivering and receiving portion delivering and receiving the substratebetween the vapor processing portion and the aligner.
 16. The apparatusas set forth in claim 12, wherein the apparatus is disposed adjacent toan aligner, the apparatus further comprising: a delivering and receivingportion delivering and receiving the substrate between the dryingprocessing portion and the aligner.
 17. The apparatus as set forth inclaim 10, wherein the vapor processing portion has a pressurecontrolling portion controlling a pressure of the atmosphere around thesubstrate.
 18. The apparatus as set forth in claim 17, wherein thepressure controlling portion controls the pressure so that the pressurebecomes higher than an atmospheric pressure for a predetermined timeperiod beginning from when the substrate is started to be placed in thevapor and controls the pressure so that the pressure becomes lower thanthe atmospheric pressure after the predetermined time period.